Did you watch the video? The man who should do something big for BTC doesn't even know how to scan QR codes, and these two who assist him are not exactly experts - so I honestly doubt that DT even knew exactly what he was doing, although not exactly in the way that Biden would have done it, but not too far from it.
In other words, the former president did nothing but watch others do what they called the US president's first transaction - which by the way was not made from his smartphone, and even less with his BTC.